Abstract: A charged material containing a metal raw material of at least one of ferrochromium containing metal Si or ferrosilicon and unreduced slag containing Cr oxide generated by oxidation refining is charged into an AC electric furnace including three electrodes, a mass ratio of a metal Si amount to a Cr oxide amount being from 0.30 to 0.40, and a C concentration being from 2.0% by mass to a saturation concentration.

Abstract: Provided is an image forming apparatus in which, while image formation is prevented from being performed, scattered toner that has dropped from a filter and adhered to an outer peripheral surface of a developer carrying member is recovered. A fixed magnet of the developer carrying member has a first pole that is arranged to face the filter, and a second pole and a third pole on a downstream side relative to the first pole. The first pole and the second pole have polarities opposite to each other, and the second pole and the third pole have a same polarity. A length of a gap between the developing container and an area where the developing sleeve faces the second pole among areas of the developing sleeve is smaller than a length between the developing sleeve and the filter.

Abstract: A print medium is conveyed in a first direction and a printing head prints an image on the print medium by using a printable region of the print head that extends in a second direction crossing the first direction. Storing units can feed multiple sorts of print media. Among the multiple sorts of the print media, the print medium to print a check pattern for checking a printing state of the printing head is selected as the print medium to be fed from the corresponding storing unit. The check pattern is printed on the print medium by using a portion of the printable region of the printing head corresponding to a size of the print medium fed from the storing unit.

Abstract: Provided is an image forming apparatus that is capable of carrying out a scattered-toner recovery mode in which, while image formation is prevented from being performed, scattered toner that has dropped from a filter and adhered to an outer peripheral surface of a developer carrying member is recovered by a cleaning unit through intermediation of an image bearing member. A fixed magnet of the developer carrying member has a first pole that faces the image bearing member, a second pole that faces the filter, and an intermediate pole between the first pole and the second pole.

Abstract: Provided is an image forming apparatus in which, while image formation is prevented from being performed, scattered toner that has dropped from a filter and adhered to an outer peripheral surface of a developer carrying member is recovered by a cleaning unit through intermediation of an image bearing member. An absolute value of a perpendicular-magnetic-force gradient of a fixed magnet of the developer carrying member is 4.0 mT/° or less at a position where the fixed magnet faces a central portion of the filter in a rotation direction of a developing sleeve.

Abstract: A developing device includes a developer container and a developer carrying member. The developer carrying member includes a shaft, a sleeve that rotates while carrying toner on its outer circumferential face, and a magnet that extends along the axis of the developer carrying member. The developer container includes a duct, an intake port which opens above the developer carrying member and through which the inside of the developer container and the inside of the duct communicate with each other, and a first filter that covers the intake port. The edges of the first filter at one side and at the other side in the axial direction of the developer carrying member are both located within a range opposite the magnet as seen from the direction perpendicular to the axial direction.

Abstract: The developing device includes a development container, a developer carrier, and a toner trapping mechanism. The development container includes a first conveyance chamber and a second conveyance chamber placed in parallel juxtaposition and communicated with each other at their longitudinal both end portions, and the development container contains a toner-containing developer to be fed to an image carrier. The toner trapping mechanism includes a duct, an air inlet port, an air exhaust port, a filter, and a fan. The air inlet port is placed at a connecting portion between the duct and the second conveyance chamber, and opened along the longitudinal direction of the second conveyance chamber so as to allow air present in the second conveyance chamber to flow into the duct. The air exhaust port is placed downstream of the air inlet port as viewed in a developer conveyance direction of the second conveyance chamber.

Abstract: The developing device includes a development container, a developer carrier, and a toner trapping mechanism. The development container includes a first conveyance chamber and a second conveyance chamber placed in parallel juxtaposition and communicated with each other at their longitudinal both end portions, and the development container contains a toner-containing developer to be fed to an image carrier. The toner trapping mechanism includes a duct, an air inlet port, a trapping filter, and a fan. The duct is connected to the second conveyance chamber, and allows air present in the second conveyance chamber to flow therethrough. The development container has an air vent opened in the first conveyance chamber and communicated with outside of the development container.

Abstract: The image forming apparatus includes a developing part and a vibration generating part. The vibration generating part vibrates a filter provided in the developing part. The developing part includes a development container, a developer carrier, and a toner trapping mechanism. The development container includes a first conveyance chamber and a second conveyance chamber placed in parallel juxtaposition. The toner trapping mechanism has a duct, an air inlet port, an air exhaust port, and a filter. The air inlet port is opened along the longitudinal direction of the second conveyance chamber so as to allow air present in the second conveyance chamber to flow into the duct. The vibration generating part is placed outside the developing part so as to be opposed to the development container and positioned on a downstream side in a developer conveyance direction of the second conveyance chamber.

Abstract: An image forming apparatus includes a development device, and a control unit that controls the development device. The development device includes a toner collection mechanism having a duct, a filter, and an exhaust fan. The duct is connected to a conveyance chamber of the development container and allows air in the conveyance chamber to flow through. The filter is disposed at a connecting part between the duct and the conveyance chamber, and collects toner flowing into the duct from the conveyance chamber. The exhaust fan makes the air in the conveyance chamber flow to the outside via the duct. The control unit changes rotational frequency or operation frequency of the exhaust fan based on current detected by a current detection unit at non-image forming time.

Abstract: An image forming apparatus includes an image carrier, a cleaning unit, a development device, and a control unit. The development device includes a toner collection mechanism having a developer carrier and a filter. The control unit is capable of executing a scattered toner recovery mode at non-image forming time, in which the filter is vibrated, a potential difference is generated in the direction for the toner to move from the developer carrier to the image carrier, the developer carrier is rotated in a reverse direction to that at image forming time, and the image carrier is rotated in the same direction as that at the image forming time, so that scattered toner, which has dropped from the filter and adhered to the developer carrier, is recovered by the cleaning unit via the image carrier.

Abstract: Formed is a dither pattern that makes it possible to output an image with excellent dot dispersibility and reduced graininess regardless of controls after quantization processing. To this end, an extended pattern in which multiple divided pixels correspond to each of multiple pixels included in quantization data and one or more of the multiple divided pixels are determined as dot-arrangeable-pixels in which dots can be printed is generated. Thereafter, the thresholds of the dither pattern are set based on the extended pattern in which the dots are arranged to obtain predetermined dispersibility.

Abstract: An object is to print a high quality image with resistance to print misalignment. To this end, the image processing apparatus generates quantized data for printing a first dot pattern and a second dot pattern in an overlapping manner. The first dot pattern and the second dot pattern are lattice patterns varying in a combination of two basis vectors. In a combined dot pattern obtained by combining the first and second dot patterns, there is a neighboring dot in which a dot in the first dot pattern and a dot in the second dot pattern are arranged at an interval smaller than a lattice spacing. The neighboring dot includes multiple neighboring dots varying in an approach direction.

Abstract: A first dot pattern printed according to a result of quantization performed on a multi-valued grayscale value by using a first threshold matrix and a second dot pattern printed according to a result of quantization performed on multi-valued grayscale value by using a second threshold matrix are printed on a print medium in an overlapping manner. In order to generate the threshold matrices, a first initial pattern being a dot pattern corresponding to a first grayscale value and a second initial pattern being a dot pattern corresponding to a second grayscale value lower than the first grayscale value are generated for pixel regions of the first and second threshold matrices. Then, thresholds of the first and second threshold matrices are set such that dot patterns having continuity with the first and second initial patterns are obtained at grayscale values between the first and second grayscale values.

Abstract: An image forming apparatus includes a development device, and a control unit that controls the development device. The development device includes a toner collection mechanism having a duct, a filter, and an exhaust fan. The duct is connected to a conveyance chamber of the development container and allows air in the conveyance chamber to flow through. The filter is disposed at a connecting part between the duct and the conveyance chamber, and collects toner flowing into the duct from the conveyance chamber. The exhaust fan makes the air in the conveyance chamber flow to the outside via the duct. The control unit changes rotational frequency or operation frequency of the exhaust fan based on current detected by a current detection unit at non-image forming time.

Abstract: Provided is an image forming apparatus in which, while image formation is prevented from being performed, scattered toner that has dropped from a filter and adhered to an outer peripheral surface of a developer carrying member is recovered by a cleaning unit through intermediation of an image bearing member. An absolute value of a perpendicular-magnetic-force gradient of a fixed magnet of the developer carrying member is 4.0 mT/° or less at a position where the fixed magnet faces a central portion of the filter in a rotation direction of a developing sleeve.

Abstract: Provided is an image forming apparatus in which, while image formation is prevented from being performed, scattered toner that has dropped from a filter and adhered to an outer peripheral surface of a developer carrying member is recovered. A fixed magnet of the developer carrying member has a first pole that is arranged to face the filter, and a second pole and a third pole on a downstream side relative to the first pole. The first pole and the second pole have polarities opposite to each other, and the second pole and the third pole have a same polarity. A length of a gap between the developing container and an area where the developing sleeve faces the second pole among areas of the developing sleeve is smaller than a length between the developing sleeve and the filter.

Abstract: An image forming apparatus includes an image carrier, a cleaning unit, a development device, and a control unit. The development device includes a toner collection mechanism having a developer carrier and a filter. The control unit is capable of executing a scattered toner recovery mode at non-image forming time, in which the filter is vibrated, a potential difference is generated in the direction for the toner to move from the developer carrier to the image carrier, the developer carrier is rotated in a reverse direction to that at image forming time, and the image carrier is rotated in the same direction as that at the image forming time, so that scattered toner, which has dropped from the filter and adhered to the developer carrier, is recovered by the cleaning unit via the image carrier.

Abstract: Provided is an image forming apparatus that is capable of carrying out a scattered-toner recovery mode in which, while image formation is prevented from being performed, scattered toner that has dropped from a filter and adhered to an outer peripheral surface of a developer carrying member is recovered by a cleaning unit through intermediation of an image bearing member. A fixed magnet of the developer carrying member has a first pole that faces the image bearing member, a second pole that faces the filter, and an intermediate pole between the first pole and the second pole.

Abstract: An object is to print a high quality image with resistance to print misalignment. To this end, the image processing apparatus generates quantized data for printing a first dot pattern and a second dot pattern in an overlapping manner. The first dot pattern and the second dot pattern are lattice patterns varying in a combination of two basis vectors. In a combined dot pattern obtained by combining the first and second dot patterns, there is a neighboring dot in which a dot in the first dot pattern and a dot in the second dot pattern are arranged at an interval smaller than a lattice spacing. The neighboring dot includes multiple neighboring dots varying in an approach direction.